1. Technical Field
The inventive concept relates to a semiconductor device, and more particularly, to a high voltage switch and a nonvolatile memory device including the same.
2. Discussion of the Related Art
Semiconductor memory devices may be volatile or nonvolatile. The volatile semiconductor memory devices may perform read and write operations at a high speed, but lose data when their power supply is off or interrupted. The nonvolatile semiconductor memory devices do not require a maintained power supply and can retain data even when not powered. Thus, the nonvolatile semiconductor memory devices are used to store data which must be retained when power is gone.
A flash memory device is a type of nonvolatile semiconductor memory device. The flash memory device may be used as a voice and image data storing medium of information appliances such as a computer, a cellular phone, a personal digital assistant (PDA), a digital camera, a camcorder, a voice recorder, an MP3 player, a handheld personal computer (PC), a game machine, a facsimile, a scanner, a printer, and the like.
A high voltage Vpp higher than a power supply voltage VDD may be provided to the flash memory device from an external device. A high voltage of about 20V may be used to program and erase memory cells of the flash memory device. A high voltage switch for controlling the high voltage Vpp may also be provided. However, the high voltage Vpp supplied from the external device may be decreased below a reference value due to external factors. In this case, a leakage current path may be generated between the power supply voltage VDD and the high voltage Vpp.